This invention relates generally to surgical clips and, more particularly, to clips for temporarily occluding blood vessels during surgery.
A wide variety of surgical clips have been proposed heretofore for purposes of vascular occlusion. However, many of these clips have been constructed in a manner such that they directly squeeze or pinch the vessel closed between opposing and converging flat surfaces. The clamping action of these prior clips necessarily gives rise to the possibility of damage or rupture of the vessel as a result of their intrusive pinching or crushing effect on the clamped vessel. Other clips, as exemplified by the clips described in U.S. Pat. Nos. 3,996,937 and 4,024,868, have been constructed to avoid this pinching or crushing action on the vessel. However, those clips are designed to cause permanent occlusion and are not suitable for temporary occlusion in view of the closure action of the metallic rod-like clamping members which exert relatively high pressure on the clamped vessels and cause complete collapse of the vessel walls.
Thus, it has been a continuing problem in the design of surgical clips to develop a clip for the temporary occlusion of blood vessels which is effective in stopping blood flow without causing permanent occlusion or present risk of traumatic damage to the vessel.
A further problem which has been encountered with prior surgical clips is that they have been manufactured and stored in a stressed condition. Over a period of time, such devices lose their elasticity and upon application may not provide the necessary clamping force or pressure to occlude a vessel and, if sufficient pressure is not exerted, the potential exists for slippage or disengagement of the clip from the vessel.